I don't know KM media, but there are quite a number of similar case in Microbial media. What we do is:1- Mix everything that can be autoclaved together at 2X and adjust final volume to just have to add:2- Everything that cannot be autoclaved is mixed in the minimal amount of water and filter sterilized3- Autoclave 1 and let it cool down4- Add 2

Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)

I think, that canalon wrote it a little bit not clear, so imagine, you wish to do 0.5 l of your media. So mix everything, that can be autoclaved in amount for 0.5 l, but dissolve in e.g. 400 ml, so you have left 100 ml for additives, which will you filter